1. Field of the Invention
The present invention relates to air-conditioning systems for motor vehicles and, in particular, to air-conditioning systems for motor vehicles having adsorption heat pumps.
2. Discussion of Background Information
Air-conditioning systems for motor vehicles are currently implemented by compression refrigerating machines which are driven by motors using V-belts. R134a (Tetrafluoroethane) is typically used as a refrigerant. The disadvantage of this is that R134a and other HFHC have a high greenhouse potential. Because of the high leak rates in motor vehicle air-conditioning systems, the use of less harmful refrigerants, such as CO2, is being developed. However, the significant additional fuel consumption of approximately 1 l/100 km/h may not be reduced in this way. Compression refrigerating machines also may not typically be operated when the drive engine of the motor vehicle is turned off. This results in uncomfortably high stationary temperatures. The high stationary temperatures also require a high-performance design for the compression refrigerating machines to achieve pleasant temperatures in the vehicle interior within an acceptably short time after the drive engine has been started.
Because of the above-mentioned disadvantages, there have been various attempts to use thermally driven heat pumps, in particular adsorption heat pumps, for air conditioning motor vehicles. However, these attempts have not yet been able to prevail in the market up to this point, because they occupy too much space.